I think thoughtful use of rivers, with few bridges, would have been a good way to provide extra choke points or channeling of armies towards one another without having quite so many mountains; I think that would make for a more realistic and appealing map- you wouldn't have to make it an absolutely impassable obstacle either, you could provide realistic but inconvenient options such as making a fleet of rafts to take an army across, but this would require time and wood harvested from a nearby forest to accomplish (my idea is you would have to go to the forest and spend time harvesting timber on the world map, then carry these materials to the river).
Also, there could be alternative routes to a lot of areas, but alternatives which have costs to them. So going the 'other' way might involve traversing a high moorland (or desert or marsh, etc.) where there is not much food to forage and it is cold, reducing morale and increasing attrition (men either dying of illness or deserting), plus there may not be useful paths because it is not a commonly used route, meaning your travel speed would be slower. The upside to using this route may be to bypass an enemy castle or avoid an army you know or expect to be waiting for you, or to avoid crossing the territory of a neutral faction who you don't want to anger.
Also, there could be alternative routes to a lot of areas, but alternatives which have costs to them. So going the 'other' way might involve traversing a high moorland (or desert or marsh, etc.) where there is not much food to forage and it is cold, reducing morale and increasing attrition (men either dying of illness or deserting), plus there may not be useful paths because it is not a commonly used route, meaning your travel speed would be slower. The upside to using this route may be to bypass an enemy castle or avoid an army you know or expect to be waiting for you, or to avoid crossing the territory of a neutral faction who you don't want to anger.









